Is it possible to find new Birfs for an FJ62 in town on a Saturday? I am rebuilding my front axle this weekend and just want to know what I can accomplish if I get the axle apart and find that I have a bad birfield while I'm in there.

In a stupid offsite meeting all day, but I'll check later for answers.

Thanks in advance! Paul

nakman

12-07-2007, 09:43 AM

Do you suspect you've got a bad one? Does one side not work in 4WD, or do you get a lot of clicking when in 4WD? I'm not sure how a birfield would just "go bad," particularly in a part-time truck. I'd personally be more worried about having all the gaskets, enough grease, maybe one extra inner axle seal just in case you miss while installing it, stuff like that..

But I suspect all the dealers would have them if you realy had to buy a new one. And if you wanted a used one, I suspect someone on the list here would have one available. Are 62 birfs the same as 40 birfs? I've got a couple 40 birfs kicking around somewhere, but don't remember the spline count off the top of my head..

Uncle Ben

12-07-2007, 10:00 AM

Are 62 birfs the same as 40 birfs? I've got a couple 40 birfs kicking around somewhere, but don't remember the spline count off the top of my head..

Only after '79. the later model ones are the more desirable as they are heat treated and have less of a relief cut into the bell. '79< in Cruisers and Minis are the same until 86 for the minis and 91 on the Cruisers.

Turtle60

12-08-2007, 05:47 PM

Well, I got one cleaned up and it looks like there is a groove all the way around the inside where the ball bearings ride. It is deeper at one edge than the other. How deep can the groove be before it should be replaced? I can cacth a finger nail on it. Truck has 220k miles, probably the original joints.

nakman

12-08-2007, 09:21 PM

There are little indentations from where the balls hit it? What some do is swap the birfs left to right, then put them back in and call it good for another 100,000 miles. IMO on a part time truck or non-wheeler I really wouldn't worry about it. Post up some pics though if you want more opinions..

Turtle60

12-10-2007, 10:28 PM

Here is an okay picture of the groove. Any thoughts? What about the brass bushings in the spindle? There is a visible wear area on the bottom portion of each of them whhere the birf rides. Marlin carries them, but they are expensive! $35 for a piece of brass. This thing is killing me! Well, it will be ready for another 200k after this - if the diff lasts.

Engine is stock 350, no hp mods, 31" tires - not really going to go big on anything for awhile. Mostly use 4wheel for ice, deep snow and going fishing back in on some dirt roads/river crossings

nakman

12-10-2007, 10:39 PM

Well those are fairly deep, not too bad though. Again since you're only P/T 4wd it's hard to say how long they will last.. on 31's? I'd have to think for a long time. If you swapped them L to R you could even out the wear a little bit more, and be pushing against the "good spot" of the bell when going forward. But, when in reverse you'd have the worst of all situations, that being the weaker direction and the weaker portion of the ball. But as long as your wheels aren't turned and you're not trying to yank someone you should be fine.

I guess you have to decide if you want to plunk the money now for piece of mind, or wait until you break one. How much is a stock birfield? Have you tried to find a good used one? Here's one alternative to OEM if you want to beef up.. http://www.longfieldsuperaxles.com/